Feature:1. Made of classic carbon steel material, drill bit has high hardness, strong cutting force2. Widely used in DIY, household and general construction or engineering use, etc3. With good centering and no slipping,drill bit set is able to drill glossy holes quickly and accurately4. Fiveside chamfer design, automatically and quickly discharge the chips in the holes on both sides, and improve the drilling efficiency5. The countersunk drill bit kit includes 5 sizes to meet your various needs, and each drill bit comes with a plastic box marked with a size to facilitate your identification and storageSpecification:Item Type: Countersink Drill Bit SetMaterial: 45#Carbon SteelCounterbore Size: Approx. 2.8 x 8mm / 0.1 x 0.3inApprox. 3 x 8mm / 0.1 x 0.3inApprox. 3.2 x 8mm / 0.13 x 0.3inApprox. 3.5 x 8mm / 0.14 x 0.3inApprox. 4 x 8mm / 0.16 x 0.3in.Package List:5 x Countersink Drills5 x Wrenches5 x The Spare Screws5 x Plastic Packaging BoxsNote:1.Use the center punch to locate before drilling, keep the drill bit vertical, and prevent the drill bit from bending or breaking2.Please allow 0‑2 cm error due to manual measurement. Thanks for your understanding